1. Field of the Invention
The present invention relates to an electrical connector and, in particular, to an electrical connector having a self-retained boardlock for securing the electrical connector to a printed circuit board ("PCB").
2. Description of the Prior Art
Numerous techniques are known for securing electrical connectors to printed circuit boards. For example, corresponding through holes may be provided in the electrical connectors and the printed circuit boards for accepting a screw and a nut which are tightened to secure the connector to the printed circuit board. Such a technique works quite well but is relatively tedious and requires substantial assembly time. As a result, boardlocks, clips, and the like have been developed for securing the electrical connector to the printed circuit board without the use of any tools.
Boardlocks, clips, and the like come in numerous shapes and sizes and are generally passed through apertures in the electrical connector and the printed circuit board for securing the electrical connector to the printed circuit board. The hold down mechanism typically comprises "Christmas tree-shaped" barbs on the boardlock or clip which engage the printed circuit board to provide an interference fit with the boardlock receiving aperture of the printed circuit board. The boardlocks, clips, and the like are typically retained in the boardlock receiving aperture of the electrical connector housing prior to connection to the printed circuit board by way of an interference fit between the boardlock and the boardlock receiving aperture of the electrical connector as described, for example, by Douty et al. in U.S. Pat. No. 4,907,987, by Hypes in U.S. Pat. No. 5,080,611, and by Sitzler in U.S. Pat. No. 5,135,412. Other boardlocks, clips, and the like are shipped separately from the electrical connectors or are constrained in narrow through slots and the like in the electrical connector using projections such as barbs which extend through the through slots of the electrical connector to fasten the electrical connector in position relative to corresponding holes in the printed circuit board. Such fasteners are described, for example, by Ishikawa in U.S. Pat. No. 5,184,963 and are also illustrated in Japanese Pat. No. 61-28905. Still other electrical connectors use clips or lock pins for mounting the electrical connector on the printed circuit board without the use of barbs. Such clips or lock pins are described, for example, by Olsson in U.S. Pat. No. 4,645,287 and by Nakazawa et al. in U.S. Pat. No. 4,681,389.
Unfortunately, boardlocks, clips, and lock pins of the type described in the aforementioned patents cannot readily be shipped with the electrical connectors without falling out or otherwise separating from the electrical connectors. Due to the small size of these elements, it is generally undesirable that they be shipped separately. Indeed, even boardlocks with an interference fit may back out of the boardlock retaining apertures of the electrical connectors and be separated from the electrical connectors during shipment.
Accordingly, an improved boardlock is desired which retains itself within the boardlock retaining aperture of the electrical connector so that it will not fall out or back out during shipment of the electrical connector. It is also desired that the boardlock be usable in conventional screw and hex nut apertures so that additional tooling of the electrical connector is not required and so that the purchaser will have numerous assembly options. The present invention has been designed to meet these needs.